Ultra-reliable low-latency communication over sidelink

ABSTRACT

Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a transmitter user equipment (UE) may transmit, to a receiver UE, a stage one sidelink control information (SCI) message that indicates one or more sub-channels occupied by the transmitter UE. The transmitter UE may transmit, to the receiver UE, a physical sidelink shared channel (PSSCH) using the one or more sub-channels occupied by the transmitter UE according to a configured grant associated with the transmitter UE. Numerous other aspects are provided.

FIELD OF THE DISCLOSURE

Aspects of the present disclosure generally relate to wirelesscommunication and to techniques and apparatuses for ultra-reliablelow-latency communication (URLLC) over a sidelink.

BACKGROUND

Wireless communication systems are widely deployed to provide varioustelecommunication services such as telephony, video, data, messaging,and broadcasts. Typical wireless communication systems may employmultiple-access technologies capable of supporting communication withmultiple users by sharing available system resources (e.g., bandwidth,transmit power, and/or the like). Examples of such multiple-accesstechnologies include code division multiple access (CDMA) systems, timedivision multiple access (TDMA) systems, frequency-division multipleaccess (FDMA) systems, orthogonal frequency-division multiple access(OFDMA) systems, single-carrier frequency-division multiple access(SC-FDMA) systems, time division synchronous code division multipleaccess (TD-SCDMA) systems, and Long Term Evolution (LTE).LTE/LTE-Advanced is a set of enhancements to the Universal MobileTelecommunications System (UMTS) mobile standard promulgated by theThird Generation Partnership Project (3GPP).

A wireless network may include a number of base stations (BSs) that cansupport communication for a number of user equipment (UEs). A userequipment (UE) may communicate with a base station (BS) via the downlinkand uplink. The downlink (or forward link) refers to the communicationlink from the BS to the UE, and the uplink (or reverse link) refers tothe communication link from the UE to the BS. As will be described inmore detail herein, a BS may be referred to as a Node B, a gNB, anaccess point (AP), a radio head, a transmit receive point (TRP), a NewRadio (NR) BS, a 5G Node B, and/or the like.

The above multiple access technologies have been adopted in varioustelecommunication standards to provide a common protocol that enablesdifferent user equipment to communicate on a municipal, national,regional, and even global level. New Radio (NR), which may also bereferred to as 5G, is a set of enhancements to the LTE mobile standardpromulgated by the Third Generation Partnership Project (3GPP). NR isdesigned to better support mobile broadband Internet access by improvingspectral efficiency, lowering costs, improving services, making use ofnew spectrum, and better integrating with other open standards usingorthogonal frequency division multiplexing (OFDM) with a cyclic prefix(CP) (CP-OFDM) on the downlink (DL), using CP-OFDM and/or SC-FDM (e.g.,also known as discrete Fourier transform spread OFDM (DFT-s-OFDM)) onthe uplink (UL), as well as supporting beamforming, multiple-inputmultiple-output (MIMO) antenna technology, and carrier aggregation. Asthe demand for mobile broadband access continues to increase, furtherimprovements in LTE, NR, and other radio access technologies remainuseful.

SUMMARY

In some aspects, a method of wireless communication, performed by atransmitter user equipment (UE), may include: transmitting, to areceiver UE, a stage one sidelink control information (SCI) message thatindicates one or more sub-channels occupied by the transmitter UE; andtransmitting, to the receiver UE, a physical sidelink shared channel(PSSCH) using the one or more sub-channels occupied by the transmitterUE according to a configured grant associated with the transmitter UE.

In some aspects, a transmitter UE for wireless communication may includea memory and one or more processors operatively coupled to the memory.The memory and the one or more processors may be configured to:transmit, to a receiver UE, a stage one SCI message that indicates oneor more sub-channels occupied by the transmitter UE; and transmit, tothe receiver UE, a PSSCH using the one or more sub-channels occupied bythe transmitter UE according to a configured grant associated with thetransmitter UE.

In some aspects, a non-transitory computer-readable medium may store oneor more instructions for wireless communication. The one or moreinstructions, when executed by one or more processors of a transmitterUE, may cause the one or more processors to: transmit, to a receiver UE,a stage one SCI message that indicates one or more sub-channels occupiedby the transmitter UE; and transmit, to the receiver UE, a PSSCH usingthe one or more sub-channels occupied by the transmitter UE according toa configured grant associated with the transmitter UE.

In some aspects, an apparatus for wireless communication may include:means for transmitting, to a receiver UE, a stage one SCI message thatindicates one or more sub-channels occupied by the apparatus; and meansfor transmitting, to the receiver UE, a PSSCH using the one or moresub-channels occupied by the apparatus according to a configured grantassociated with the apparatus.

Aspects generally include a method, device, apparatus, system, computerprogram product, non-transitory computer-readable medium, userequipment, base station, wireless communication device, and/orprocessing system as substantially described herein with reference toand as illustrated by the drawings and specification.

The foregoing has outlined rather broadly the features and technicaladvantages of examples according to the disclosure in order that thedetailed description that follows may be better understood. Additionalfeatures and advantages will be described hereinafter. The conceptionand specific examples disclosed may be readily utilized as a basis formodifying or designing other structures for carrying out the samepurposes of the present disclosure. Such equivalent constructions do notdepart from the scope of the appended claims. Characteristics of theconcepts disclosed herein, both their organization and method ofoperation, together with associated advantages will be better understoodfrom the following description when considered in connection with theaccompanying figures. Each of the figures is provided for the purposesof illustration and description, and not as a definition of the limitsof the claims.

BRIEF DESCRIPTION OF THE DRAWINGS

So that the above-recited features of the present disclosure can beunderstood in detail, a more particular description, briefly summarizedabove, may be had by reference to aspects, some of which are illustratedin the appended drawings. It is to be noted, however, that the appendeddrawings illustrate only certain typical aspects of this disclosure andare therefore not to be considered limiting of its scope, for thedescription may admit to other equally effective aspects. The samereference numbers in different drawings may identify the same or similarelements.

FIG. 1 is a diagram illustrating an example of a wireless network, inaccordance with various aspects of the present disclosure.

FIG. 2 is a diagram illustrating an example of a base station incommunication with a UE in a wireless network, in accordance withvarious aspects of the present disclosure.

FIG. 3 is a diagram illustrating an example of sidelink communications,in accordance with various aspects of the present disclosure.

FIG. 4 is a diagram illustrating an example of sidelink communicationsand access link communications, in accordance with various aspects ofthe present disclosure.

FIG. 5 is a diagram illustrating an example of a delay-constraineddeployment, in accordance with various aspects of the presentdisclosure.

FIGS. 6A-6B are diagrams illustrating examples of ultra-reliablelow-latency communication (URLLC), in accordance with various aspects ofthe present disclosure.

FIG. 7 is a diagram illustrating an example of an industrialInternet-of-Things (IIoT) deployment supporting URLLC over a sidelink,in accordance with various aspects of the present disclosure.

FIGS. 8A-8C are diagrams illustrating examples associated with URLLCover a sidelink, in accordance with various aspects of the presentdisclosure.

FIGS. 9A-9D are diagrams illustrating examples associated with URLLCover a sidelink, in accordance with various aspects of the presentdisclosure.

FIG. 10 is a diagram illustrating an example process associated withURLLC over a sidelink, in accordance with various aspects of the presentdisclosure.

FIG. 11 is a block diagram of an example apparatus for wirelesscommunication, in accordance with various aspects of the presentdisclosure.

DETAILED DESCRIPTION

Various aspects of the disclosure are described more fully hereinafterwith reference to the accompanying drawings. This disclosure may,however, be embodied in many different forms and should not be construedas limited to any specific structure or function presented throughoutthis disclosure. Rather, these aspects are provided so that thisdisclosure will be thorough and complete, and will fully convey thescope of the disclosure to those skilled in the art. Based on theteachings herein, one skilled in the art should appreciate that thescope of the disclosure is intended to cover any aspect of thedisclosure disclosed herein, whether implemented independently of orcombined with any other aspect of the disclosure. For example, anapparatus may be implemented or a method may be practiced using anynumber of the aspects set forth herein. In addition, the scope of thedisclosure is intended to cover such an apparatus or method which ispracticed using other structure, functionality, or structure andfunctionality in addition to or other than the various aspects of thedisclosure set forth herein. It should be understood that any aspect ofthe disclosure disclosed herein may be embodied by one or more elementsof a claim.

Several aspects of telecommunication systems will now be presented withreference to various apparatuses and techniques. These apparatuses andtechniques will be described in the following detailed description andillustrated in the accompanying drawings by various blocks, modules,components, circuits, steps, processes, algorithms, and/or the like(collectively referred to as “elements”). These elements may beimplemented using hardware, software, or combinations thereof. Whethersuch elements are implemented as hardware or software depends upon theparticular application and design constraints imposed on the overallsystem.

It should be noted that while aspects may be described herein usingterminology commonly associated with a 5G or NR radio accesstechnologies (RAT), aspects of the present disclosure can be applied toother RATs, such as a 3G RAT, a 4G RAT, and/or a RAT subsequent to 5G(e.g., 6G).

FIG. 1 is a diagram illustrating an example of a wireless network 100,in accordance with various aspects of the present disclosure. Thewireless network 100 may be or may include elements of a 5G (NR)network, an LTE network, and/or the like. The wireless network 100 mayinclude a number of base stations 110 (shown as BS 110 a, BS 110 b, BS110 c, and BS 110 d) and other network entities. A base station (BS) isan entity that communicates with user equipment (UEs) and may also bereferred to as an NR BS, a Node B, a gNB, a 5G node B (NB), an accesspoint, a transmit receive point (TRP), and/or the like. Each BS mayprovide communication coverage for a particular geographic area. In3GPP, the term “cell” can refer to a coverage area of a BS and/or a BSsubsystem serving this coverage area, depending on the context in whichthe term is used.

ABS may provide communication coverage for a macro cell, a pico cell, afemto cell, and/or another type of cell. A macro cell may cover arelatively large geographic area (e.g., several kilometers in radius)and may allow unrestricted access by UEs with service subscription. Apico cell may cover a relatively small geographic area and may allowunrestricted access by UEs with service subscription. A femto cell maycover a relatively small geographic area (e.g., a home) and may allowrestricted access by UEs having association with the femto cell (e.g.,UEs in a closed subscriber group (CSG)). ABS for a macro cell may bereferred to as a macro BS. ABS for a pico cell may be referred to as apico BS. A BS for a femto cell may be referred to as a femto BS or ahome BS. In the example shown in FIG. 1 , a BS 110 a may be a macro BSfor a macro cell 102 a, a BS 110 b may be a pico BS for a pico cell 102b, and a BS 110 c may be a femto BS for a femto cell 102 c. A BS maysupport one or multiple (e.g., three) cells. The terms “eNB”, “basestation”, “NR BS”, “gNB”, “TRP”, “AP”, “node B”, “5G NB”, and “cell” maybe used interchangeably herein.

In some aspects, a cell may not necessarily be stationary, and thegeographic area of the cell may move according to the location of amobile BS. In some aspects, the BSs may be interconnected to one anotherand/or to one or more other BSs or network nodes (not shown) in thewireless network 100 through various types of backhaul interfaces suchas a direct physical connection, a virtual network, and/or the likeusing any suitable transport network.

Wireless network 100 may also include relay stations. A relay station isan entity that can receive a transmission of data from an upstreamstation (e.g., a BS or a UE) and send a transmission of the data to adownstream station (e.g., a UE or a BS). A relay station may also be aUE that can relay transmissions for other UEs. In the example shown inFIG. 1 , a relay station 110 d may communicate with macro BS 110 a and aUE 120 d in order to facilitate communication between BS 110 a and UE120 d. A relay station may also be referred to as a relay BS, a relaybase station, a relay, and/or the like.

Wireless network 100 may be a heterogeneous network that includes BSs ofdifferent types, e.g., macro BSs, pico BSs, femto BSs, relay BSs, and/orthe like. These different types of BSs may have different transmit powerlevels, different coverage areas, and different impacts on interferencein wireless network 100. For example, macro BSs may have a high transmitpower level (e.g., 5 to 40 watts) whereas pico BSs, femto BSs, and relayBSs may have lower transmit power levels (e.g., 0.1 to 2 watts).

A network controller 130 may couple to a set of BSs and may providecoordination and control for these BSs. Network controller 130 maycommunicate with the BSs via a backhaul. The BSs may also communicatewith one another, e.g., directly or indirectly via a wireless orwireline backhaul.

UEs 120 (e.g., 120 a, 120 b, 120 c) may be dispersed throughout wirelessnetwork 100, and each UE may be stationary or mobile. A UE may also bereferred to as an access terminal, a terminal, a mobile station, asubscriber unit, a station, and/or the like. A UE may be a cellularphone (e.g., a smart phone), a personal digital assistant (PDA), awireless modem, a wireless communication device, a handheld device, alaptop computer, a cordless phone, a wireless local loop (WLL) station,a tablet, a camera, a gaming device, a netbook, a smartbook, anultrabook, a medical device or equipment, biometric sensors/devices,wearable devices (smart watches, smart clothing, smart glasses, smartwrist bands, smart jewelry (e.g., smart ring, smart bracelet)), anentertainment device (e.g., a music or video device, or a satelliteradio), a vehicular component or sensor, smart meters/sensors,industrial manufacturing equipment, a global positioning system device,or any other suitable device that is configured to communicate via awireless or wired medium.

Some UEs may be considered machine-type communication (MTC) or evolvedor enhanced machine-type communication (eMTC) UEs. MTC and eMTC UEsinclude, for example, robots, drones, remote devices, sensors, meters,monitors, location tags, and/or the like, that may communicate with abase station, another device (e.g., remote device), or some otherentity. A wireless node may provide, for example, connectivity for or toa network (e.g., a wide area network such as Internet or a cellularnetwork) via a wired or wireless communication link. Some UEs may beconsidered Internet-of-Things (IoT) devices, and/or may be implementedas NB-IoT (narrowband Internet-of-Things) devices. Some UEs may beconsidered a Customer Premises Equipment (CPE). UE 120 may be includedinside a housing that houses components of UE 120, such as processorcomponents, memory components, and/or the like. In some aspects, theprocessor components and the memory components may be coupled together.For example, the processor components (e.g., one or more processors) andthe memory components (e.g., a memory) may be operatively coupled,communicatively coupled, electronically coupled, electrically coupled,and/or the like.

In general, any number of wireless networks may be deployed in a givengeographic area. Each wireless network may support a particular RAT andmay operate on one or more frequencies. A RAT may also be referred to asa radio technology, an air interface, and/or the like. A frequency mayalso be referred to as a carrier, a frequency channel, and/or the like.Each frequency may support a single RAT in a given geographic area inorder to avoid interference between wireless networks of different RATs.In some cases, NR or 5G RAT networks may be deployed.

In some aspects, two or more UEs 120 (e.g., shown as UE 120 a and UE 120e) may communicate directly using one or more sidelink channels (e.g.,without using a base station 110 as an intermediary to communicate withone another). For example, the UEs 120 may communicate usingpeer-to-peer (P2P) communications, device-to-device (D2D)communications, a vehicle-to-everything (V2X) protocol (e.g., which mayinclude a vehicle-to-vehicle (V2V) protocol, a vehicle-to-infrastructure(V2I) protocol, and/or the like), a mesh network, and/or the like. Inthis case, the UE 120 may perform scheduling operations, resourceselection operations, and/or other operations described elsewhere hereinas being performed by the base station 110.

Devices of wireless network 100 may communicate using theelectromagnetic spectrum, which may be subdivided based on frequency orwavelength into various classes, bands, channels, and/or the like. Forexample, devices of wireless network 100 may communicate using anoperating band having a first frequency range (FR1), which may span from410 MHz to 7.125 GHz, and/or may communicate using an operating bandhaving a second frequency range (FR2), which may span from 24.25 GHz to52.6 GHz. The frequencies between FR1 and FR2 are sometimes referred toas mid-band frequencies. Although a portion of FR1 is greater than 6GHz, FR1 is often referred to as a “sub-6 GHz” band. Similarly, FR2 isoften referred to as a “millimeter wave” band despite being differentfrom the extremely high frequency (EHF) band (30 GHz-300 GHz) which isidentified by the International Telecommunications Union (ITU) as a“millimeter wave” band. Thus, unless specifically stated otherwise, itshould be understood that the term “sub-6 GHz” or the like, if usedherein, may broadly represent frequencies less than 6 GHz, frequencieswithin FR1, and/or mid-band frequencies (e.g., greater than 7.125 GHz).Similarly, unless specifically stated otherwise, it should be understoodthat the term “millimeter wave” or the like, if used herein, may broadlyrepresent frequencies within the EHF band, frequencies within FR2,and/or mid-band frequencies (e.g., less than 24.25 GHz). It iscontemplated that the frequencies included in FR1 and FR2 may bemodified, and techniques described herein are applicable to thosemodified frequency ranges.

In some aspects, wireless network 100 may support Industrial IoT (IIoT)communications, which generally refers to a branch of cellulartechnology in which UEs 120 and base stations 110 may be used tocommunicate control data, measurement data, and/or the like betweenvarious industrial systems. For example, IIoT may be used to control asensor device and/or an actuator device, to exchange measurementinformation between programmable logic controllers (PLCs) of a factoryfloor (e.g., in a factory automation application), and/or the like. Inmany applications, IIoT traffic is treated as ultra-reliable low-latencycommunication (URLLC) traffic, which imparts strict latency andreliability requirements. In some cases, in addition to URLLC trafficbetween UEs 120 and base stations 110, IIoT traffic may also usesidelink communications between UEs 120 (e.g., between a PLC UE 120 anda sensor/actuator (S/A) UE 120). For example, IIoT traffic may behandled over a sidelink in deployments with poor network coverage or nonetwork coverage (e.g., in a shielded production cell), to support usecases with a high degree of cooperation among robots and/or or otherindustrial systems, to offload factory traffic (e.g., using the sidelinkfor maintenance between a maintaining tablet and an on-demand sensorwithout interrupting URLLC-based closed-loop control), and/or the like.

However, sidelink communications typically cannot meet stringent URLLClatency and reliability requirements because sidelink communicationshave relaxed quality of service (QoS) requirements, lower radioefficiency for carrying traffic relative to an access link used forcommunication between a UE 120 and a base station 110, and/or the like.Accordingly, some aspects described herein relate to techniques andapparatuses to satisfy URLLC requirements over a sidelink. For example,some aspects described herein may conduct an initial transmission usinga configured grant or semi-persistent scheduling (SPS) configuration toreduce control overhead. Additionally, or alternatively, some aspectsdescribed herein may support retransmissions that are triggered by anegative acknowledgement (NACK) (e.g., rather than performing blindretransmissions, as in a typical sidelink implementation) to improveradio efficiency. Additionally, or alternatively, some aspects describedherein may utilize a mini-slot based resource allocation to reducetransmission times, provide multiple switching points within a slot, andfacilitate fast switching (e.g., between transmission directions) withina slot. In this way, sidelink communications in a delay-constraineddeployment, such as an IIoT deployment, may satisfy stringent latencyand reliability requirements.

As indicated above, FIG. 1 is provided as an example. Other examples maydiffer from what is described with regard to FIG. 1 .

FIG. 2 is a diagram illustrating an example 200 of a base station 110 incommunication with a UE 120 in a wireless network 100, in accordancewith various aspects of the present disclosure. Base station 110 may beequipped with T antennas 234 a through 234 t, and UE 120 may be equippedwith R antennas 252 a through 252 r, where in general T≥1 and R≥1.

At base station 110, a transmit processor 220 may receive data from adata source 212 for one or more UEs, select one or more modulation andcoding schemes (MCS) for each UE based at least in part on channelquality indicators (CQIs) received from the UE, process (e.g., encodeand modulate) the data for each UE based at least in part on the MCS(s)selected for the UE, and provide data symbols for all UEs. Transmitprocessor 220 may also process system information (e.g., for semi-staticresource partitioning information (SRPI) and/or the like) and controlinformation (e.g., CQI requests, grants, upper layer signaling, and/orthe like) and provide overhead symbols and control symbols. Transmitprocessor 220 may also generate reference symbols for reference signals(e.g., a cell-specific reference signal (CRS), a demodulation referencesignal (DMRS), and/or the like) and synchronization signals (e.g., theprimary synchronization signal (PSS) and secondary synchronizationsignal (SSS)). A transmit (TX) multiple-input multiple-output (MIMO)processor 230 may perform spatial processing (e.g., precoding) on thedata symbols, the control symbols, the overhead symbols, and/or thereference symbols, if applicable, and may provide T output symbolstreams to T modulators (MODs) 232 a through 232 t. Each modulator 232may process a respective output symbol stream (e.g., for OFDM and/or thelike) to obtain an output sample stream. Each modulator 232 may furtherprocess (e.g., convert to analog, amplify, filter, and upconvert) theoutput sample stream to obtain a downlink signal. T downlink signalsfrom modulators 232 a through 232 t may be transmitted via T antennas234 a through 234 t, respectively.

At UE 120, antennas 252 a through 252 r may receive the downlink signalsfrom base station 110 and/or other base stations and may providereceived signals to demodulators (DEMODs) 254 a through 254 r,respectively. Each demodulator 254 may condition (e.g., filter, amplify,downconvert, and digitize) a received signal to obtain input samples.Each demodulator 254 may further process the input samples (e.g., forOFDM and/or the like) to obtain received symbols. A MIMO detector 256may obtain received symbols from all R demodulators 254 a through 254 r,perform MIMO detection on the received symbols if applicable, andprovide detected symbols. A receive processor 258 may process (e.g.,demodulate and decode) the detected symbols, provide decoded data for UE120 to a data sink 260, and provide decoded control information andsystem information to a controller/processor 280. The term“controller/processor” may refer to one or more controllers, one or moreprocessors, or a combination thereof. A channel processor may determinereference signal received power (RSRP), received signal strengthindicator (RSSI), reference signal received quality (RSRQ), channelquality indicator (CQI), and/or the like. In some aspects, one or morecomponents of UE 120 may be included in a housing 284.

Network controller 130 may include communication unit 294,controller/processor 290, and memory 292. Network controller 130 mayinclude, for example, one or more devices in a core network. Networkcontroller 130 may communicate with base station 110 via communicationunit 294.

On the uplink, at UE 120, a transmit processor 264 may receive andprocess data from a data source 262 and control information (e.g., forreports that include RSRP, RSSI, RSRQ, CQI, and/or the like) fromcontroller/processor 280. Transmit processor 264 may also generatereference symbols for one or more reference signals. The symbols fromtransmit processor 264 may be precoded by a TX MIMO processor 266 ifapplicable, further processed by modulators 254 a through 254 r (e.g.,for DFT-s-OFDM, CP-OFDM, and/or the like), and transmitted to basestation 110. In some aspects, the UE 120 includes a transceiver. Thetransceiver may include any combination of antenna(s) 252, modulatorsand/or demodulators 254, MIMO detector 256, receive processor 258,transmit processor 264, and/or TX MIMO processor 266. The transceivermay be used by a processor (e.g., controller/processor 280) and memory282 to perform aspects of any of the methods described herein, forexample, as described with reference to FIG. 7 , FIGS. 8A-8C, FIGS.9A-9D, and/or FIGS. 10-11 .

At base station 110, the uplink signals from UE 120 and other UEs may bereceived by antennas 234, processed by demodulators 232, detected by aMIMO detector 236 if applicable, and further processed by a receiveprocessor 238 to obtain decoded data and control information sent by UE120. Receive processor 238 may provide the decoded data to a data sink239 and the decoded control information to controller/processor 240.Base station 110 may include communication unit 244 and communicate tonetwork controller 130 via communication unit 244. Base station 110 mayinclude a scheduler 246 to schedule UEs 120 for downlink and/or uplinkcommunications. In some aspects, the base station 110 includes atransceiver. The transceiver may include any combination of antenna(s)234, modulators and/or demodulators 232, MIMO detector 236, receiveprocessor 238, transmit processor 220, and/or TX MIMO processor 230. Thetransceiver may be used by a processor (e.g., controller/processor 240)and memory 242 to perform aspects of any of the methods describedherein, for example, as described with reference to FIG. 7 , FIGS.8A-8C, FIGS. 9A-9D, and/or FIGS. 10-11 .

Controller/processor 240 of base station 110, controller/processor 280of UE 120, and/or any other component(s) of FIG. 2 may perform one ormore techniques associated with ultra-reliable low-latency communication(URLLC) over a sidelink, as described in more detail elsewhere herein.For example, controller/processor 240 of base station 110,controller/processor 280 of UE 120, and/or any other component(s) ofFIG. 2 may perform or direct operations of, for example, process 1000 ofFIG. 10 and/or other processes as described herein. Memories 242 and 282may store data and program codes for base station 110 and UE 120,respectively. In some aspects, memory 242 and/or memory 282 may includea non-transitory computer-readable medium storing one or moreinstructions (e.g., code, program code, and/or the like) for wirelesscommunication. For example, the one or more instructions, when executed(e.g., directly, or after compiling, converting, interpreting, and/orthe like) by one or more processors of the base station 110 and/or theUE 120, may cause the one or more processors, the UE 120, and/or thebase station 110 to perform or direct operations of, for example,process 1000 of FIG. 10 and/or other processes as described herein. Insome aspects, executing instructions may include running theinstructions, converting the instructions, compiling the instructions,interpreting the instructions, and/or the like.

In some aspects, UE 120 may include means for transmitting, to areceiver UE 120, a stage one sidelink control information (SCI) messagethat indicates one or more sub-channels occupied by UE 120, means fortransmitting, to the receiver UE 120, a physical sidelink shared channel(PSSCH) using the one or more sub-channels occupied by UE 120 accordingto a configured grant associated with UE 120, and/or the like. In someaspects, such means may include one or more components of UE 120described in connection with FIG. 2 , such as controller/processor 280,transmit processor 264, TX MIMO processor 266, MOD 254, antenna 252,DEMOD 254, MIMO detector 256, receive processor 258, and/or the like.

While blocks in FIG. 2 are illustrated as distinct components, thefunctions described above with respect to the blocks may be implementedin a single hardware, software, or combination component or in variouscombinations of components. For example, the functions described withrespect to the transmit processor 264, the receive processor 258, and/orthe TX MIMO processor 266 may be performed by or under the control ofcontroller/processor 280.

As indicated above, FIG. 2 is provided as an example. Other examples maydiffer from what is described with regard to FIG. 2 .

FIG. 3 is a diagram illustrating an example 300 of sidelinkcommunications, in accordance with various aspects of the presentdisclosure.

As shown in FIG. 3 , a first UE 305-1 may communicate with a second UE305-2 (and/or one or more other UEs 305) via one or more sidelinkchannels 310. The UEs 305-1 and 305-2 may communicate using the one ormore sidelink channels 310 for P2P communications, D2D communications,IIoT communications, V2X communications (e.g., which may include V2Vcommunications, V2I communications, V2P communications, and/or thelike), mesh networking, and/or the like. In some aspects, the UEs 305(e.g., UE 305-1 and/or UE 305-2) may correspond to one or more other UEsdescribed elsewhere herein, such as UE 120. In some aspects, the one ormore sidelink channels 310 may use a PC5 interface and/or may operate ina high frequency band (e.g., the 5.9 GHz band). Additionally, oralternatively, the UEs 305 may synchronize timing of transmission timeintervals (TTIs) (e.g., frames, subframes, slots, symbols, and/or thelike) using global navigation satellite system (GNSS) timing.

As further shown in FIG. 3 , the one or more sidelink channels 310 mayinclude a physical sidelink control channel (PSCCH) 315, a physicalsidelink shared channel (PSSCH) 320, a physical sidelink feedbackchannel (PSFCH) 325, and/or the like. The PSCCH 315 may be used tocommunicate control information, similar to a physical downlink controlchannel (PDCCH) and/or a physical uplink control channel (PUCCH) usedfor cellular communications with a base station 110 via an access linkor an access channel. The PSSCH 320 may be used to communicate data,similar to a physical downlink shared channel (PDSCH) and/or a physicaluplink shared channel (PUSCH) used for cellular communications with abase station 110 via an access link or an access channel. For example,the PSCCH 315 may carry sidelink control information (SCI) 330, whichmay indicate various control information used for sidelinkcommunications, such as one or more resources (e.g., time resources,frequency resources, spatial resources, and/or the like) where atransport block (TB) 335 may be carried on the PSSCH 320. The TB 335 mayinclude data. The PSFCH 325 may be used to communicate sidelink feedback340, such as hybrid automatic repeat request (HARD) feedback (e.g.,acknowledgement or negative acknowledgement (ACK/NACK) information),transmit power control (TPC), a scheduling request (SR), and/or thelike.

In some aspects, the one or more sidelink channels 310 may use resourcepools. For example, a scheduling assignment (e.g., included in SCI 330)may be transmitted in sub-channels using specific resource blocks (RBs)across time. In some aspects, data transmissions (e.g., on the PSSCH320) associated with a scheduling assignment may occupy adjacent RBs inthe same subframe as the scheduling assignment (e.g., using frequencydivision multiplexing). In some aspects, a scheduling assignment andassociated data transmissions are not transmitted on adjacent RBs.

In some aspects, a UE 305 may operate using a transmission mode whereresource selection and/or scheduling is performed by the UE 305 (e.g.,rather than a base station 110). In some aspects, the UE 305 may performresource selection and/or scheduling by sensing channel availability fortransmissions. For example, the UE 305 may measure a received signalstrength indicator (RSSI) parameter (e.g., a sidelink-RSSI (S-RSSI)parameter) associated with various sidelink channels, may measure areference signal received power (RSRP) parameter (e.g., a PSSCH-RSRPparameter) associated with various sidelink channels, may measure areference signal received quality (RSRQ) parameter (e.g., a PSSCH-RSRQparameter) associated with various sidelink channels, and/or the like,and may select a channel for transmission of a sidelink communicationbased at least in part on the measurement(s).

Additionally, or alternatively, the UE 305 may perform resourceselection and/or scheduling using SCI 330 received in the PSCCH 315,which may indicate occupied resources, channel parameters, and/or thelike. Additionally, or alternatively, the UE 305 may perform resourceselection and/or scheduling by determining a channel busy rate (CBR)associated with various sidelink channels, which may be used for ratecontrol (e.g., by indicating a maximum number of resource blocks thatthe UE 305 can use for a particular set of subframes).

In the transmission mode where resource selection and/or scheduling isperformed by a UE 305, the UE 305 may generate sidelink grants, and maytransmit the grants in SCI 330. A sidelink grant may indicate, forexample, one or more parameters (e.g., transmission parameters) to beused for an upcoming sidelink transmission, such as one or more resourceblocks to be used for the upcoming sidelink transmission on the PSSCH320 (e.g., for TBs 335), one or more subframes to be used for theupcoming sidelink transmission, a modulation and coding scheme (MCS) tobe used for the upcoming sidelink transmission, and/or the like. In someaspects, a UE 305 may generate a sidelink grant that indicates one ormore parameters for SPS, such as a periodicity of a sidelinktransmission. Additionally, or alternatively, the UE 305 may generate asidelink grant for event-driven scheduling, such as for an on-demandsidelink message.

As indicated above, FIG. 3 is provided as an example. Other examples maydiffer from what is described with respect to FIG. 3 .

FIG. 4 is a diagram illustrating an example 400 of sidelinkcommunications and access link communications, in accordance withvarious aspects of the present disclosure.

As shown in FIG. 4 , a transmitter (Tx)/receiver (Rx) UE 405 and anRx/Tx UE 410 may communicate with one another via a sidelink, asdescribed above in connection with FIG. 3 . As further shown, in somesidelink modes, a base station 110 may communicate with the Tx/Rx UE 405via a first access link. Additionally, or alternatively, in somesidelink modes, the base station 110 may communicate with the Rx/Tx UE410 via a second access link. The Tx/Rx UE 405 and/or the Rx/Tx UE 410may correspond to one or more UEs described elsewhere herein, such asthe UE 120 of FIG. 1 . Thus, a direct link between UEs 120 (e.g., via aPC5 interface) may be referred to as a sidelink, and a direct linkbetween a base station 110 and a UE 120 (e.g., via a Uu interface) maybe referred to as an access link. Sidelink communications may betransmitted via the sidelink, and access link communications may betransmitted via the access link. An access link communication may beeither a downlink communication (from a base station 110 to a UE 120) oran uplink communication (from a UE 120 to a base station 110).

As indicated above, FIG. 4 is provided as an example. Other examples maydiffer from what is described with respect to FIG. 4 .

FIG. 5 is a diagram illustrating an example 500 of a delay-constraineddeployment, in accordance with various aspects of the presentdisclosure. In some aspects, the delay-constrained deployment shown inFIG. 5 may be an industrial Internet-of-Things (IIoT) deployment oranother suitable deployment in which packets are transmitted andreceived with delay constraints, reliability constraints, and/or thelike. As shown in FIG. 5 , the delay-constrained deployment may includea management system 505, one or more human-machine interfaces (HMIs)510, one or more programmable logic controller (PLC) UEs 515, and one ormore sensor/actuator (S/A) UEs 520.

Management system 505 may include a computer, such as an industrialpersonal computer or network controller 130, among otherpossibilities/examples. Management system 505 may perform controllerprogramming, software and security management, or long-term keyperformance indicator (KPI) monitoring, among otherpossibilities/examples. In some aspects, management system 505 mayperform one or more of the operations described herein as beingperformed by network controller 130.

HMI 510 may include a user device, such as a tablet computer, a laptopcomputer, a wearable device (e.g., a smart wristwatch or smarteyeglasses, and/or the like), a mobile phone, a virtual reality device,an augmented reality device, and/or the like. HMI 510 may be used tocontrol one or more machines (e.g., S/A UEs 520) at a factory-floorlevel. In some aspects, HMI 510 may provide for changing an operationalmode of an S/A UE 520.

PLC UE 515 may include a processor (e.g., a central processing unit(CPU), a graphics processing unit (GPU), an accelerated processing unit(APU), a microprocessor, a microcontroller, a digital signal processor(DSP), a field-programmable gate array (FPGA), an application-specificintegrated circuit (ASIC), or another type of processing component). PLCUE 515 may communicate with a base station 110 on an access link usinguplink/downlink communications or may be associated with a base station110 that communicates with one or more S/A UEs 520 on an access linkusing uplink/downlink communications. In some aspects, PLC UE 515 maycommunicate with one or more S/A UEs 520 using sidelink communications.In some aspects, PLC UE 515 may issue commands and receive sensor inputsin real-time or near real-time from S/A UE 520. In some aspects, PLC UEs515 and management system 505 may be associated with a backhaul, such asa wireless or wireline backhaul.

S/A UE 520 may include a sensor, an actuator, or another type of IIoTdevice. For example, S/A UE 520 may be a sensor or actuator, such as arotary motor, a linear servo, or a position sensor, among otherpossibilities/examples. In some aspects, S/A UE 520 may include a UE120, may be included in a UE 120, or may be associated with a UE 120(such that S/A UE 520 communicates with UE 120 using sidelinkcommunications). In some aspects, S/A UE 520 may be associated with aradio interface via which to communicate with a given PLC UE 515. Theradio interface may be scheduled by a base station 110 associated withPLC UE 515 and/or configured based at least in part on configurationinformation provided by management system 505.

In some aspects, the radio interface may carry data communicationsbetween S/A UE 520 (or an associated UE 120) and a base station 110,such as a data communication carrying a status update report associatedwith an S/A UE 520 or a data communication carrying sensor measurementsassociated with an S/A UE 520, among other possibilities/examples.Moreover, the radio interface may carry HARQ feedback associated withthe data communications between S/A UE 520 (or an associated UE 120) anda base station 110, a PLC UE 515, and/or the like. For example, in someaspects, the HARQ feedback may include an ACK that may be associatedwith a data communication to indicate that the S/A UE 520 successfullyreceived and decoded the data communication and/or a NACK associatedwith a data communication to indicate that the S/A UE 520 fails toreceive or successfully decode the data communication.

As indicated above, FIG. 5 is provided as an example. Other examples maydiffer from what is described with regard to FIG. 5 .

FIGS. 6A-6B are diagrams illustrating examples 600 of ultra-reliablelow-latency communication (URLLC), in accordance with various aspects ofthe present disclosure. For example, as described herein, a wirelessnetwork (e.g., wireless network 100) may offer URLLC service to supportuse cases in which a base station 110 and a UE 120 need to communicateover an access link using a low-latency requirement and/or a highreliability requirement, generally referred to herein as a URLLCrequirement. In URLLC, for example, the base station 110 and the UE 120may be required to satisfy a URLLC requirement in which communicating apacket with a small payload size (e.g., less than or equal to 32 bytes,256 bytes, and/or the like) satisfies a target reliability metric (e.g.,a block error rate (BLER) of 10⁻⁶ or better, a reliability of 99.999% orbetter, and/or the like) and a target latency (e.g., an end-to-endlatency of one millisecond or less). Accordingly, URLLC service may beprovided on an access link (e.g., a Uu interface) in a wireless network,such as a 5G or NR network, to support use cases with stringentreliability and latency requirements, which may include public safety,remote diagnosis/surgery, emergency response, autonomous driving, smartenergy and grid management, and factory automation, among others.

For example, as shown in FIG. 6A, and by reference number 610, an IIoT(or factory automation) deployment may satisfy a URLLC latencyobjective. As shown, a sensor in an IIoT deployment may transmit acommunication to an embedded computing node, which may forward thecommunication to a transmitter associated with the IIoT deployment. Thetransmitter may transmit the communication to a receiver associated witha wireless network (e.g., a receiver associated with a base station110), which may route the communication to a control/steering server tobe processed. After the control/steering server has processed thecommunication, a response communication may be provided from thecontrol/steering server to a transmitter associated with the wirelessnetwork (e.g., a transmitter associated with the base station 110),which may transmit the response communication to a receiver associatedwith the IIoT deployment.

The receiver may then route the communication to the embedded computingnode, which forwards the response communication to an actuator that mayperform an action based at least in part on the response communication.Accordingly, to satisfy the URLLC latency objective of a low end-to-endlatency (e.g., one millisecond or less), a user interface (e.g., theembedded computing node and the transmitter/receiver associated with theIIoT deployment) may need to have a low one-way latency (e.g., 0.3milliseconds or less), and a radio interface (e.g., between thetransmitter/receiver associated with the IIoT deployment and thereceiver/transmitter associated with the wireless network) may need tohave a low one-way latency (e.g., 0.2 milliseconds or less).

To satisfy the stringent reliability and latency requirements associatedwith URLLC service, a radio interface (e.g., an access link or Uuinterface) may be designed to efficiently allocate resources to supportcommunication between base stations and UEs. For example, as shown inFIG. 6B, and by reference number 620, URLLC service may be enabled by amini-slot resource allocation to reduce transmission times, facilitatemultiple switching points within a slot, facilitate fast switching(e.g., between downlink and uplink, or vice versa), and/or the like. Forexample, in a wireless network that supports a scalable numerology, ashorter transmission time can generally be achieved with a largersubcarrier spacing.

Accordingly, the mini-slot resource allocation may define a schedulingunit that is smaller than a typical slot, which enables a URLCCtransmission to be quickly scheduled to meet stringent latencyrequirements. For example, in FIG. 6B, one standard scheduling slot isdivided into four mini-slots, which include two mini-slots for downlinkcommunication and two mini-slots for uplink communication. Furthermore,the mini-slot resource allocation may enable URLLC transmissions topreempt other transmissions to immediately transmit data that requireslow latency. For example, when resources are unavailable for a URLLCtransmission, the URLLC transmission can be scheduled on resources thatoverlap with ongoing transmissions for other service types (e.g., eMBB),and the preempted transmission can be handled by HARQ feedback, apreemption indication, and/or the like.

Furthermore, as shown by reference number 620, URLLC service may besupported by using SPS for initial transmissions, which enables radioresources to be semi-statically configured and allocated to a UE for alonger time period than one subframe, which may avoid the need forspecific downlink assignment messages and/or uplink grant messages overa PDCCH for each subframe. To configure SPS, radio resource control(RRC) signaling may indicate an interval at which the radio resourcesare periodically assigned.

PDCCH signaling may indicate specific transmission resource allocationsin the time/frequency domain and transmission attributes (e.g.,periodicity, MCS, time offset, transmit power, and/or the like).Furthermore, URLLC service may enable uplink data transmissions that maybe performed without a dynamic grant, generally referred to as aconfigured grant (CG). More particularly, in a Type 1 CG configuration,a UE can perform uplink data transmission without a grant based at leastin part on RRC (re)configuration without any Layer-1 (L1) signaling, andin a Type 2 CG configuration, the UE can perform uplink datatransmission without a grant based at least in part on RRC(re)configuration in combination with L1 signaling (e.g., downlinkcontrol information) to activate and/or release the Type 2 CGconfiguration.

Furthermore, as shown by reference number 640, a wireless network maysupport URLLC service by using PDCCH-scheduled retransmissions that aretriggered by a negative acknowledgement (NACK). For example, rather thanperforming blind retransmissions, which may reduce network capacity,retransmissions may be triggered only when a transmitter receives a NACKfor an initial transmission. For example, on a downlink, a base stationmay conduct an initial SPS-based downlink transmission in a firstdownlink mini-slot, which includes an uplink control portion in which aUE transmits HARQ feedback to indicate whether the initial downlinktransmission was successfully received. Accordingly, the first downlinkmini-slot is followed by a second downlink mini-slot in which the basestation may transmit a PDCCH to schedule a retransmission for a UE thatindicates a NACK for the initial downlink transmission.

Similarly, on an uplink, a UE may conduct an initial uplink transmissionin a first uplink mini-slot (e.g., using a configured grant), whichincludes an uplink common burst portion in which the UE may receive HARQfeedback from the base station indicating whether the initial uplinktransmission was successfully received. Accordingly, the first uplinkmini-slot is followed by a second uplink mini-slot in which the basestation may transmit a PDCCH to dynamically schedule a retransmission ofthe initial uplink transmission. In this way, by only conductingretransmissions when triggered by a NACK, radio resource efficiency isimproved.

Although URLLC service may be supported on an access link or Uuinterface using a mini-slot resource allocation, initial downlink and/oruplink transmissions without a dynamic grant (e.g., using SPS or a CG),NACK-triggered retransmissions, and/or the like, there are variousscenarios in which access link communications may be unavailable orrestricted and/or sidelink communications are more efficient than accesslink communications. For example, in an IIoT deployment, access linkcommunications may be unavailable in environments with poor networkcoverage or no network coverage (e.g., in a shielded production cell).In such an example, sidelink communications may be used to enablecooperative operation among robots or other industrial machines on afactory floor. Sidelink communications may also be used to offloadnetwork traffic (e.g., by using a sidelink for maintenance between amaintenance device, such as a tablet, and an on-demand sensor withoutinterrupting URLLC-based closed loop control), and/or the like.

However, sidelink communications are typically not designed to satisfythe stringent reliability and latency requirements associated with URLLCuse cases. For example, sidelink communications are often designed witha focus on V2X cases, which typically relate to peer-to-peercommunications and enabling proper operation when UEs are out of thecoverage area of a cellular network. For example, in a sidelinktransmission mode (e.g., Mode 2) where resource selection and/orscheduling is performed by a UE to support sidelink operation in theabsence of a cellular network, distributed resource allocation typicallyrelies on autonomous sensing for distributed channel access, whichcauses significant overhead to facilitate sensing. Accordingly, becausesidelink communications often have relaxed quality of service (QoS)requirements, especially with respect to the low latency (e.g., onemillisecond) that is required for factory automation and other URLLC usecases, a sidelink or PC5 interface generally has a much lower radioefficiency for carrying traffic compared to an access link or Uuinterface. As a result, existing techniques for enabling sidelinkcommunications between UEs lack the efficiency to support URLLC traffic.

Some aspects described herein relate to techniques and apparatuses tosupport URLLC traffic over a sidelink. For example, some aspectsdescribed herein relate to sidelink control information (SCI)configurations that may enable an initial transmission to be conductedusing a CG (or similar) configuration to reduce control overhead,support NACK-triggered retransmissions to improve radio efficiency,and/or the like. Additionally, or alternatively, some aspects describedherein may utilize a mini-slot based resource allocation to reducetransmission times, provide multiple switching points within a slot, andfacilitate fast switching (e.g., between transmission directions) withina slot. In this way, some aspects described herein may enable compliancewith stringent URLLC latency and reliability requirements for sidelinkcommunications in a delay-constrained deployment, such as an IIoTdeployment.

As indicated above, FIGS. 6A-6B are provided as examples. Other examplesmay differ from what is described with regard to FIGS. 6A-6B.

FIG. 7 is a diagram illustrating an example 700 of an IIoT deploymentsupporting URLLC over a sidelink, in accordance with various aspects ofthe present disclosure. As shown in FIG. 7 , example 700 includes a basestation 110 that may communicate with one or more PLC UEs 712 and one ormore S/A UEs 714 over an access link or Uu interface, which may providea low-rate control channel (e.g., when the IIoT deployment is providedin a shielded production cell or another environment with poor networkcoverage or no network coverage). Accordingly, the IIoT deployment mayrely upon sidelink communications for various operations due to theunavailability or limited availability of the access link or Uuinterface. For example, as shown, the IIoT deployment includes anon-demand sensor 716 that may communicate with a maintenance device 718using a sidelink or PC5 interface, which may provide an on-demandhigh-rate data channel (e.g., to offload traffic from the access link).Furthermore, in some aspects, each PLC UE 712 may communicate with oneor more S/A UEs 714 over a URLLC sidelink (e.g., in a star topology thatis coordinated by the base station 110, coordinated among the differentPLC UEs 712, coordinated by the maintenance device 718, and/or thelike). As described herein, the URLLC sidelink may provide a strongradio frequency channel that can be used for high-data rate and controlin a manner that may satisfy stringent reliability and latencyrequirements.

For example, as described above, URLLC service may be supported on anaccess link or Uu interface by various techniques, which may includeconducting initial transmissions without requiring a dynamic grant(e.g., using an SPS configuration for an initial downlink transmissionor a CG configuration for an initial uplink transmission) to reducecontrol overhead, conducting only NACK-triggered retransmissions toimprove radio efficiency, providing a mini-slot resource allocation toreduce transmission times and provide multiple switching points within aslot, and/or the like. Accordingly, some aspects described herein maypropagate one or more techniques that are used to support URLLC serviceon an access link or Uu interface to the URLLC sidelink provided on aPC5 interface between the PLC UEs 712 and the S/A UEs 714. For example,as described herein, the URLLC sidelink may be implemented using a SCIconfiguration that enables the PC5 interface to satisfy high-reliabilityand low-latency requirements while also maintaining backwardcompatibility with existing sidelink communication techniques.

For example, existing sidelink communication techniques are generallyassociated with a physical (PHY) layer configuration and/or a low mediumaccess control (MAC) layer configuration that uses two-stage SCI toindicate various parameters to control sidelink transmissions. Inparticular, a stage one SCI carried over a PSCCH is generally used toindicate a channel use or resource reservation, and the stage one SCI isblindly decoded by all UEs. The stage one SCI may also contain a pointerto a stage two SCI, which is carried over a PSSCH to indicate additionalparameters, such as a transmitter identifier, a receiver identifier, anMCS, HARQ control information associated with a transport blocktransmitted over the PSSCH, and/or the like. Furthermore, a transmittingUE may transmit the SCI even for a configured grant PSSCH that may betransmitted without a dynamic grant. In some aspects, as described infurther detail with reference to FIGS. 8A-8C and FIGS. 9A-9D, the URLLCsidelink implemented on the PC5 interface between the PLC UEs 712 andthe S/A UEs 714 may be based at least in part on the two-stage SCI inwhich a transmitting UE may broadcast or multicast the stage one SCI toone or more receiver UEs and/or transmit the stage two SCI to furtherindicate UE-specific information.

Furthermore, unicast sidelink communications (e.g., between onetransmitter UE and one receiver UE) may be established throughupper-layer MAC and higher protocols (e.g., sidelink or PC5 radioresource control (RRC) signaling). Although using upper-layer MAC andhigher protocols to establish unicast communications on a sidelink cansignificantly simplify a design for a physical layer and/or lower MAClayers for V2X use cases that may have relaxed QoS requirements withrespect to latency and/or the like, this technique poses challenges withrespect to arranging prompt interaction between the physical layer andlower MAC layers for two UEs communicating over a unicast sidelinkconnection. Accordingly, some aspects described herein may utilizeconfigured grants (e.g., receiver-oriented configured grants) to supportstatically or semi-statically configured interaction between thephysical layer and lower MAC layers for UEs communicating over a unicastsidelink connection. In addition, some aspects described herein mayprovide an SCI configuration that enables sidelink communications tosatisfy strict QoS requirements (e.g., reliability and/or latencyrequirements), including initial transmissions from a PLC UE 712 to oneor more S/A UEs 714, retransmissions from a PLC UE 712 to one or moreS/A UEs 714, initial transmissions from one or more S/A UEs 714 to a PLCUE 712, retransmissions from one or more S/A UEs 714 to a PLC UE 712,and/or the like.

As indicated above, FIG. 7 is provided as an example. Other examples maydiffer from what is described with regard to FIG. 7 .

FIGS. 8A-8C are diagrams illustrating one or more examples 800associated with URLLC over a sidelink, in accordance with variousaspects of the present disclosure. As shown in FIGS. 8A-8C, example(s)800 include a transmitter UE and one or more receiver UEs communicatingover a sidelink (or PC5 interface) (e.g., according to a one-to-one orone-to-many configuration). In some aspects, the transmitter UE maycorrespond to a PLC UE (e.g., PLC UE 515, PLC UE 712, and/or the like)and the receiver UEs may correspond to S/A UEs (e.g., S/A UE 520, S/A UE714, and/or the like) in an IIoT deployment, a delay-constraineddeployment, or another suitable deployment in which UE-to-UE sidelinkcommunications over a radio interface are associated with stringent QoSrequirements (e.g., high reliability, low-latency, and/or the like). Asdescribed herein, example(s) 800 relate to various techniques to enablethe transmitter UE to conduct initial transmissions and/orretransmissions to the receiver UE(s) in a manner that may satisfy thestringent QoS requirements associated with UE-to-UE sidelinkcommunications.

In some aspects, the transmitter UE and the receiver UEs may communicatein one or more delay-constrained time cycles in which a slot used forsidelink communication includes one or more transmission time intervalsthat are configured as a mini-slot (e.g., in a similar manner asillustrated in FIG. 6B). In this case, the mini-slot configuration mayinclude a first scheduling unit (e.g., a first slot) in which thetransmitter UE may transmit a PSCCH and/or an initial PSSCH transmissionand further in which the receiver UEs may transmit a PSFCH indicatingHARQ feedback for the initial PSSCH transmission. Furthermore, asdescribed herein, the mini-slot configuration may include a secondscheduling unit (e.g., a second slot) in which the transmitter UE maytransmit an additional PSCCH and/or retransmit the PSSCH for one or morereceiver UEs that indicate a NACK for the initial PSSCH transmission.

As shown in FIG. 8A, and by reference number 810, the transmitter UE maytransmit (e.g., using controller/processor 280, transmit processor 264,TX MIMO processor 266, MOD 254, antenna 252, transmission component1106, and/or the like) a PSCCH that includes a stage one sidelinkcontrol information message 812 (shown in FIG. 8A as SCI-1) togetherwith a PSSCH that includes respective configured grant data 814 to theone or more receiver UEs. For example, in some aspects, the stage oneSCI message 812 may indicate respective resource reservations that thetransmitter UE is to use to transmit the configured grant data 814 tothe one or more receiver UEs. In other words, the resource reservationsindicated in the stage one SCI message 812 may indicate a set ofsub-channels that the transmitter UE is occupying in one or moretransmission time intervals (e.g., slots, mini-slots, or otherscheduling units) in order to transmit the configured grant data 814 tothe one or more receiver UEs. For example, in FIG. 8A, the transmitterUE may transmit a PSSCH including respective configured grant data 814to five (5) receiver UEs (shown as S/A₁ through S/A₅). Accordingly, eachreceiver UE may have a receiver-oriented configured grant configurationthat enables the respective receiver UE to receive a sidelink datatransmission in a particular transmission time interval withoutrequiring a dynamic grant to schedule the sidelink data transmission.For example, in some aspects, the receiver-oriented configured grant maybe configured by a base station over access link (Uu) RRC signaling, bythe transmitter UE over sidelink (PC5) RRC signaling, and/or the like.

Accordingly, the stage one SCI message 812 may be a common (or groupcommon) stage one SCI message transmitted by the transmitter UE tooccupy all of the time and frequency resources to be used for one ormore PSSCH transmissions to one or more respective receiver UEs.Furthermore, the stage one SCI message 812 may indicate one or moretransmission parameters for all of the receiver UEs (e.g., an MCS, HARQcontrol information, channel usage or reservation information, and/orthe like). In this way, the stage one SCI message 812 may be backwardscompatible with existing SCI configurations and may enable dynamicresource coordination among different transmitter UEs (e.g., differentPLC UEs, on-demand sensors, and/or the like) by indicating time andfrequency resources that are occupied by the transmitter UE.Furthermore, in some aspects, the stage one SCI message 812 may be usedas an input to a heartbeat detection algorithm used to maintainrespective unicast connections from the transmitter UE to each receiverUE.

In some aspects, the stage one SCI message 812 in combination with therespective configured grant(s) used to transmit the PSSCH to thereceiver UE(s) may specify all parameters and related informationassociated with the transmissions of the configured grant data 814 viathe PSSCH. Accordingly, in some aspects, the transmitter UE may refrainfrom transmitting a stage two SCI message that would otherwise be usedin legacy sidelink communications to indicate UE-specific transmissionparameters (even in cases where a PSSCH is transmitted using aconfigured grant that does not require a dynamic grant) because allrelevant information is specified in the stage one SCI message 812 andthe respective configured grants. Additionally, or alternatively, thetransmitter UE may transmit additional SCI messages to one or more ofthe receiver UEs to override one or more transmission parameters thatare indicated in the common stage one SCI message 812. For example, insome aspects, the transmitter UE may transmit an additional UE-specificstage one SCI message to one or more of the receiver UEs, and theUE-specific stage one SCI message may point to a stage two SCI message.Accordingly, the transmitter UE may transmit the stage two SCI messageto the one or more receiver UEs to indicate one or more parameters thatoverride a transmission parameter, such as a modulation and codingscheme (MCS) configuration, indicated in the common stage one SCImessage 812 applicable to all of the receiver UEs.

Accordingly, as described herein, the transmitter UE may generallytransmit one stage one SCI message 812 to occupy a set of resources thatthe transmitter UE has reserved for transmitting a PSSCH to one or morereceiver UEs. For example, in the case of multiple receiver UEs, thePSSCH may include a different transport block for each receiver UE.Accordingly, each receiver UE may attempt to decode the PSSCHtransmitted to the respective receiver UE, and each respective receiverUE may transmit a PSFCH 816 that indicates an acknowledgement (ACK) ifthe PSSCH is successfully received and decoded or a NACK if the receiverUE fails to successfully receive and/or decode the PSSCH. In this way,the transmitter UE may conduct a retransmission for one or more receiverUEs that indicate a NACK for the initial PSSCH transmission, asdescribed below in connection with FIG. 8C.

As shown in FIG. 8B, and by reference number 820, the transmitter UE mayalternatively transmit (e.g., using controller/processor 280, transmitprocessor 264, TX MIMO processor 266, MOD 254, antenna 252, transmissioncomponent 1106, and/or the like) a stage one SCI message 822 that pointsto a stage two SCI message 824 indicating whether configured grant data(e.g., a PSSCH) is present for each respective receiver UE. For example,in some cases, resources to be used for a sidelink transmission to oneor more receiver UEs may be unavailable, or traffic intended for one ormore receiver UEs may be unavailable, in which case the transmitter UEmay refrain from transmitting a PSSCH to such receiver UE(s). In thiscase, the stage two SCI message 824 may include one or more presenceindicators, or presence indication information, to indicate whether aPSSCH carrying configured grant data is present on a reserved resourceindicated in the stage one SCI message 822.

Accordingly, in some aspects, the receiver UE(s) may perform non-blinddetection for the stage two SCI message 824 (e.g., when the stage oneSCI message 822 indicates that a resource is occupied for thecorresponding receiver UE) to determine whether a PSSCH carryingconfigured grant data is present on the reserved resource associatedwith the respective receiver UE. For example, the stage two SCI message824 may include a bitmap that provides presence indicators for a set ofreceiver UEs. For example, as shown in FIG. 8B, the transmitter UEtransmits a PSSCH to four receiver UEs (shown as S/A₁ through S/A₄) anddoes not transmit a PSSCH to a fifth receiver UE (shown as S/A₅).Accordingly, in this example, the bitmap may include five bits that areset to ‘11110’ to indicate that a PSSCH is present for the first fourreceiver UEs and that a PSSCH is not present for the fifth receiver UE.

Accordingly, in cases where the transmitter UE transmits the stage oneSCI message 822 that points to the stage two SCI message 824 carryingthe PSSCH presence information for one or more receiver UEs, a receiverUE may transmit a PSFCH 826 to indicate ACK/NACK feedback only in caseswhere the stage two SCI message 824 indicates that the PSSCH is presentfor the respective receiver UE. Furthermore, in some aspects, the PSSCHpresence information carried in the stage two SCI message 824 may beused to enable multi-path diversity (e.g., fast point selection) incases where there are multiple data paths from the transmitter UE to arespective receiver UE (e.g., by encoding the PSSCH presence informationto select one of the multiple data paths). Additionally, oralternatively, the PSSCH presence information carried in the stage twoSCI message 824 may be used to enable variable-rate control for one ormore receiver UEs. For example, in some cases, URLLC service may limit apayload size to 32 bytes with a one millisecond latency, but in somecases the sidelink between the transmitter UE and the receiver UE may beable to transmit a larger payload size and still satisfy a latencyconstraint. Accordingly, in some aspects, the PSSCH presence informationmay be used to encode or otherwise indicate a data rate to be used forthe sidelink transmission from the transmitter UE to the receiver UE toenable variable rate control.

As shown in FIG. 8C, and by reference number 830, the transmitter UE mayreceive (e.g., using antenna 252, DEMOD 254, MIMO detector 256, receiveprocessor 258, controller/processor 280, reception component 1102,and/or the like) ACK/NACK feedback via a PSFCH from one or more receiverUEs. For example, the transmitter UE may conduct an initial PSSCHtransmission to one or more receiver UEs as described above inconnection with FIG. 8A and/or FIG. 8B. Accordingly, the transmitter UEmay receive the ACK/NACK feedback from each receiver UE that was theintended recipient of an initial PSSCH transmission (e.g., as indicatedin a stage one and/or stage two SCI message).

As further shown in FIG. 8C, and by reference number 832, thetransmitter UE may transmit (e.g., using controller/processor 280,transmit processor 264, TX MIMO processor 266, MOD 254, antenna 252,transmission component 1106, and/or the like) a stage one SCI message834 and a stage two group SCI message 836 to schedule a PSSCHretransmission to each receiver UE that indicates a NACK for the initialPSSCH transmission. For example, in some aspects, the stage one SCImessage 834 may indicate a total resource allocation to be used forretransmissions in the slot to be used for the retransmissions (e.g., aset of sub-channels that the transmitter UE has reserved or is otherwiseoccupying for the retransmissions). Furthermore, the stage one SCImessage 834 may point to the stage two group SCI message 836, which mayinclude detailed grants for the retransmissions to each receiver UE thatindicates a NACK for the initial PSSCH transmission.

For example, in FIG. 8C, three receiver UEs (shown a S/A₁ through S/A₃)may indicate a NACK for an initial PSSCH transmission, whereby the stageone SCI message 834 may indicate the total resource usage in the slot tobe used for retransmissions to the three receiver UEs. Furthermore, thestage two SCI message 836 may include three dynamic grants schedulingthe retransmissions to each of the three receiver UEs. For example, eachdynamic grant carried in the stage two SCI message 836 may indicate oneor more sub-channels to be used for the retransmission to a respectivereceiver UE. Furthermore, in some aspects, the stage two SCI message 836may include a single cyclic redundancy check (CRC) and/or a sub-channelbased message structure to reduce overhead (e.g., relative to includinga separate CRC for each dynamic grant and/or indicating each dynamicgrant in a separate stage two SCI message). Accordingly, as furthershown by reference number 838, the receiver UEs that indicated a NACKfor the initial transmission may transmit a PSFCH to provide ACK/NACKfeedback for the PSSCH retransmission.

As indicated above, FIGS. 8A-8C are provided as examples. Other examplesmay differ from what is described with regard to FIGS. 8A-8C.

FIGS. 9A-9D are diagrams illustrating one or more examples 900associated with URLLC over a sidelink, in accordance with variousaspects of the present disclosure. As shown in FIGS. 9A-9D, example(s)900 include one or more transmitter UEs communicating with a receiver UEover a sidelink (or PC5 interface) (e.g., according to a one-to-one ormany-to-one configuration). In some aspects, the transmitter UEs maycorrespond to S/A UEs (e.g., S/A UE 520, S/A UE 714, and/or the like andthe receiver UE may correspond to a PLC UE (e.g., PLC UE 515, PLC UE712, and/or the like) in an IIoT deployment, a delay-constraineddeployment, or another suitable deployment in which UE-to-UE sidelinkcommunications over a radio interface are associated with stringent QoSrequirements (e.g., high reliability, low-latency, and/or the like). Asdescribed herein, example(s) 900 relate to various techniques to enablethe transmitter UE(s) to conduct initial transmissions and/orretransmissions the receiver UE in a manner that may satisfy thestringent QoS requirements associated with UE-to-UE sidelinkcommunications.

In some aspects, the transmitter UE and the receiver UEs may communicatein one or more delay-constrained time cycles in which a slot used forsidelink communication includes one or more transmission time intervalsthat are configured as a mini-slot (e.g., in a similar manner asillustrated in FIG. 6B). In this case, the mini-slot configuration mayinclude a first scheduling unit (e.g., a first slot) in which thetransmitter UE(s) may transmit a PSCCH and/or an initial PSSCHtransmission and further in which the receiver UE may transmit a PSFCH,an enhanced PSFCH (ePSFCH), or a further enhanced PSFCH (fePSFCH)indicating HARQ feedback for the initial PSSCH transmission.Furthermore, as described herein, the mini-slot configuration mayinclude a second scheduling unit (e.g., a second slot) in which thetransmitter UE(s) may transmit an additional PSCCH and/or retransmit thePSSCH in cases where the receiver UE indicates a NACK for one or more ofthe initial PSSCH transmissions by the one or more transmitter UEs.

As shown in FIG. 9A, and by reference number 910, one or moretransmitter UEs may each transmit (e.g., using controller/processor 280,transmit processor 264, TX MIMO processor 266, MOD 254, antenna 252,transmission component 1106, and/or the like) a stage one SCI message912 over one or more sub-channels that are occupied by the respectivetransmitter UE when using a configured grant to conduct an initialtransmission to a receiver UE. For example, in FIG. 9A, threetransmitter UEs may transmit a PSCCH that carries the stage one SCImessage 912, and the three transmitter UEs further transmit a PSSCH overone or more occupied sub-channels. For example, a first transmitter UE(S/A₁) occupying a first sub-channel to transmit a first PSSCH to thereceiver UE may transmit a first stage one SCI message 912 over thefirst sub-channel. In the same example, a second transmitter UE (S/A₂)occupying a second sub-channel to transmit a second PSSCH to thereceiver UE may transmit a second stage one SCI message 912 over thesecond sub-channel. In the same example, a third transmitter UE (S/A₃)occupying multiple sub-channels may transmit a third PSSCH to thereceiver UE may transmit a third stage one SCI message 912 over themultiple occupied sub-channels. Furthermore, as described herein, eachtransmitter UE may have a configured grant (e.g., configured by a basestation over access link or Uu RRC signaling, by the receiver UE oversidelink or PC5 RRC signaling, and/or the like) that is used to transmitthe respective PSSCH over the occupied sub-channel(s) without a dynamicgrant.

In some aspects, the stage one SCI message 912 transmitted by eachtransmitter UE may indicate radio resources (e.g., time and frequencyresources) that are occupied by the respective transmitter UE, which mayenable backward compatibility with existing sidelink communicationtechniques that use two-stage SCI. Furthermore, in a similar manner asdescribed above in connection with FIGS. 8A-8C, the stage one SCImessage 912 can be used for heartbeat detection to maintain respectiveunicast links from each respective transmitter UE to the receiver UE.Furthermore, the stage one SCI message 912 and/or the configuredgrant(s) used to transmit the PSSCH to the receiver UE may specify allparameters related to the PSSCH transmissions, whereby the transmitterUEs may refrain from transmitting a stage two SCI message that wouldotherwise be used in legacy sidelink communications to indicateUE-specific transmission parameters. Additionally, or alternatively, thetransmitter UE may transmit additional SCI to one or more of thereceiver UEs to override one or more transmission parameters. Forexample, in some aspects, one or more transmitter UEs may transmit anadditional UE-specific stage one SCI message that points to a stage twoSCI message overriding a transmission parameter, such as an MCSconfiguration, indicated in the stage one SCI message 912.

As shown in FIG. 9B, and by reference number 920, the one or moretransmitter UEs may each receive (e.g., using antenna 252, DEMOD 254,MIMO detector 256, receive processor 258, controller/processor 280,reception component 1102, and/or the like) ACK/NACK feedback via a PSFCHfrom the receiver UE. For example, the transmitter UE(s) may conduct aninitial PSSCH transmission to the receiver UE as described above inconnection with FIG. 9A. Accordingly, the transmitter UE(s) may eachreceive ACK/NACK feedback from the receiver UE indicating whether thereceiver UE successfully received and decoded, or failed to successfullyreceive and/or decode, the initial PSSCH transmission from eachrespective transmitter UE.

As further shown in FIG. 9B, and by reference number 922, the one ormore transmitter UEs may conduct (e.g., using controller/processor 280,transmit processor 264, TX MIMO processor 266, MOD 254, antenna 252,transmission component 1106, and/or the like) a multi-user MIMO(MU-MIMO) retransmission of the initial PSSCH transmissions using aconfigured grant resource that is shared among all of the transmitterUEs. For example, as shown, a stage one SCI message 924 may indicate asidelink resource 926 in a time and frequency domain that is to beshared among transmitter UEs conducting a retransmission, and thetransmitter UEs may be configured through a configured grant to sharethe sidelink resource 926 (e.g., without a dynamic grant). In someaspects, when multiple transmitter UEs are conducting retransmissionusing the shared sidelink resource 926, each respective transmitter UEmay be configured with orthogonal (or close to orthogonal) demodulationreference signal (DMRS) ports and/or sequences for the MU-MIMOretransmission. Furthermore, in some aspects, the initial PSSCHtransmissions by the one or more transmitter UEs may be associated witha target reliability metric (e.g., a block error rate (BLER)) that isselected to ensure that a number of transmitter UEs conducting theMU-MIMO retransmission does not overload the shared sidelink resource926. For example, a target BLER may be set to 10⁻², 10⁻³, and/or thelike to avoid overloading the shared sidelink resource 926 to be usedfor the MU-MIMO retransmission.

Accordingly, as shown in FIG. 9B, the transmitter UE(s) that receive aNACK from the receiver UE for the initial PSSCH transmission may jointlytransmit the stage one SCI message 924 and the corresponding PSSCHretransmissions over the shared sidelink resource 926 (e.g., radioresource). Furthermore, the shared sidelink resource 926 may beassociated with a configured grant to enable the transmitter UE(s) toconduct the MU-MIMO retransmission without a dynamic grant. In someaspects, the transmitter UEs that conduct the MU-MIMO retransmission maybe further configured to use respective power offsets that are based atleast in part on a number of other transmitter UEs that are triggered toconduct a retransmission based on a NACK from the receiver UE. Forexample, in some aspects, the respective power offsets used by thetransmitter UE(s) may be proportional to a total amount of radioresources associated with the configured grant that was used for theinitial PSSCH transmission(s).

Alternatively, as shown in FIG. 9C, and by reference number 930, the oneor more transmitter UEs may each receive (e.g., using antenna 252, DEMOD254, MIMO detector 256, receive processor 258, controller/processor 280,reception component 1102, and/or the like) ACK/NACK feedback via anenhanced PSFCH (ePSFCH) 932 transmitted by the receiver UE. In thiscase, as shown by reference number 934, the top m transmitter UEs thatreceive NACK feedback from the receiver UE may conduct (e.g., usingcontroller/processor 280, transmit processor 264, TX MIMO processor 266,MOD 254, antenna 252, transmission component 1106, and/or the like) aPSSCH retransmission using a group configured grant in theretransmission slot. For example, the parameter m may indicate themaximum number of transmitter UEs that are permitted to conduct thePSSCH retransmission using the group configured grant, and the parameterm may have a value that is configured by RRC signaling (e.g., accesslink (or Uu) RRC signaling, sidelink (or PC5) RRC signaling, and/or thelike).

Additionally, or alternatively, the value of the parameter m may beindicated in downlink control information or other suitable signalingactivating the group configured grant. For example, as shown byreference number 936, FIG. 9C illustrates a case in which m is set totwo (2), whereby a maximum of two transmitter UEs that receive NACKfeedback from the receiver UE are permitted to retransmit a PSSCH usingthe group configured grant resource. For example, as shown each of thetop m transmitter UEs that are conducting retransmission may receive anequal share of the group configured grant resource (e.g., half of thefrequency resources may be allocated to each re-transmitting UE in caseswhere m is set to 2).

In some aspects, the group configured grant may include a priority listor other priority indication for each respective transmitter UE, whichmay be used to determine the top m transmitter UEs, and the priority foreach respective transmitter UE may be time-varying according to atime-updating rule that may be specified by RRC or other suitablesignaling (e.g., to ensure that the group configured grant resource isfairly shared among all transmitter UEs). Accordingly, in some aspects,each transmitter UE may need to decode the HARQ feedback carried in theePSFCH 932 for all other transmitter UEs sharing the same groupconfigured grant to determine the number of transmitter UEs that receivea NACK from the receiver UE and to determine respective prioritiesassociated with each transmitter UE that receives a NACK from thereceiver UE. In this way, each transmitter UE that receives a NACK mayself-determine whether the respective transmitter UE is in the top mtransmitter UEs that are permitted to conduct a PSSCH retransmission inthe retransmission slot.

Alternatively, as shown in FIG. 9D, and by reference number 940, the oneor more transmitter UEs may each receive (e.g., using antenna 252, DEMOD254, MIMO detector 256, receive processor 258, controller/processor 280,reception component 1102, and/or the like) ACK/NACK feedback via afurther enhanced PSFCH (fePSFCH) 942 transmitted by the receiver UE. Inthis case, in addition to carrying ACK/NACK feedback for the initialPSCCH transmission(s) from the transmitter UE(s), the fePSFCH 942 mayinclude one or more dynamic grants for one or more retransmissions(e.g., corresponding to initial PSSCH transmissions associated with NACKfeedback). Accordingly, as shown by reference number 944, one or moretransmitter UEs that receive NACK feedback from the receiver UE and alsoreceive a dynamic grant for a retransmission may conduct (e.g., usingcontroller/processor 280, transmit processor 264, TX MIMO processor 266,MOD 254, antenna 252, transmission component 1106, and/or the like) thePSSCH retransmission using a group configured grant in theretransmission slot.

For example, as shown by reference number 946, the fePSFCH 942 receivedfrom the receiver UE may include a NACK for the initial PSSCHtransmission from a second and third transmitter UE (shown as S/A₂ andS/A₃), which are also given dynamic grants that may be separately orjointly encoded in the fePSFCH 942. Accordingly, each transmitter UEthat receives NACK feedback from the receiver UE may further determinewhether the fePSFCH 932 includes a dynamic grant for the respectivetransmitter UE, in which case the transmitter UE may retransmit thePSSCH in the retransmission slot.

Additionally, or alternatively, in some aspects, the retransmissiontechniques illustrated in FIG. 9C and FIG. 9D may be used in combinationto provide additional flexibility in scheduling sidelinkretransmissions, to enable greater sidelink retransmission capacity, toreduce overhead associated with dynamic grants used for sidelinkretransmissions, and/or the like. For example, to combine theretransmission techniques illustrated in FIG. 9C and FIG. 9D, whichrespectively use a priority list and dynamic grants to determine whichtransmitter UE(s) are to conduct a retransmission, the receiver UE mayindicate that radio resources associated with the group configured grantto be used for the PSSCH retransmission(s) are to be partitioned intotwo portions. The two portions may include a first portion to supportretransmissions by the top m transmitter UEs that receive NACK feedbackand a second portion to support retransmissions by transmitter UEs thatreceive a dynamic grant for a PSSCH retransmission. In some aspects, thefirst and second portions of the radio resources associated with thegroup configured grant may be equal, or the first and second portionsmay be unequal (e.g., to enable more flexibility, increase capacity forone group of retransmitting UEs, to reduce dynamic grant overhead,and/or the like).

Accordingly, each retransmission candidate (e.g., transmitter UE thatreceives NACK feedback) may determine whether the PSFCH (or ePSFCH orfePSFCH) includes a dynamic grant for a PSSCH retransmission. Anyretransmission candidates that receive a dynamic grant may use a shareof the second portion of the radio resources that are allocated tosupport retransmissions by the transmitter UEs that receive a dynamicgrant for a PSSCH retransmission, and each such transmitter UEs mayexclude itself from competing for the top m positions to use the otherportion of the radio resources that are allocated to supportretransmissions by the top m transmitter UEs that receive NACK feedback.Accordingly, among the remaining retransmission candidates (e.g.,transmitter UEs that received NACK feedback but did not receive adynamic grant for a PSSCH retransmission), the top m retransmissioncandidates may conduct a PSSCH retransmission using the portion of theradio resources that are allocated to support retransmissions by the topm transmitter UEs in a similar manner as described above with referenceto FIG. 9C.

As indicated above, FIGS. 9A-9D are provided as an example. Otherexamples may differ from what is described with regard to FIGS. 9A-9D.

FIG. 10 is a diagram illustrating an example process 1000 performed, forexample, by a transmitter UE, in accordance with various aspects of thepresent disclosure. Example process 1000 is an example where thetransmitter UE (e.g., UE 120, UE 305, UE 405, UE 410, S/A UE 520, S/A UE714, and/or the like) performs operations associated with URLLC over asidelink.

As shown in FIG. 10 , in some aspects, process 1000 may includetransmitting, to a receiver UE, a stage one SCI message that indicatesone or more sub-channels occupied by the transmitter UE (block 1010).For example, the transmitter UE may transmit (e.g., usingcontroller/processor 280, transmit processor 264, TX MIMO processor 266,MOD 254, antenna 252, memory 282, and/or the like), to a receiver UE, astage one SCI message that indicates one or more sub-channels occupiedby the transmitter UE, as described above.

As further shown in FIG. 10 , in some aspects, process 1000 may includetransmitting, to the receiver UE, a PSSCH using the one or moresub-channels occupied by the transmitter UE according to a configuredgrant associated with the transmitter UE (block 1020). For example, thetransmitter UE may transmit (e.g., using controller/processor 280,transmit processor 264, TX MIMO processor 266, MOD 254, antenna 252,memory 282, and/or the like), to the receiver UE, a PSSCH using the oneor more sub-channels occupied by the transmitter UE according to aconfigured grant associated with the transmitter UE, as described above.

Process 1000 may include additional aspects, such as any single aspector any combination of aspects described below and/or in connection withone or more other processes described elsewhere herein.

In a first aspect, the stage one SCI message includes a heartbeat signalto maintain a unicast link from the transmitter UE to the receiver UE.In a second aspect, alone or in combination with the first aspect,process 1000 includes transmitting, to the receiver UE, a stage two SCImessage that includes one or more parameters to override an MCSconfiguration.

In a third aspect, alone or in combination with one or more of the firstand second aspects, process 1000 includes receiving, via a PSFCH,feedback from the receiver UE indicating whether the receiver UEsuccessfully received the PSSCH, and retransmitting the PSSCH using ashared resource associated with the configured grant based at least inpart on the feedback indicating that the receiver UE failed tosuccessfully receive the PSSCH, where the transmitter UE and one or moreother transmitter UEs jointly retransmit the PSSCH using the sharedresource. In a fourth aspect, alone or in combination with one or moreof the first through third aspects, process 1000 includes transmitting,jointly with the one or more other transmitter UEs, an additional stageone SCI message indicating the shared resource used to retransmit thePSSCH. In a fifth aspect, alone or in combination with one or more ofthe first through fourth aspects, the PSSCH is retransmitted using apower offset that is based at least in part on a number of the one ormore other transmitter UEs that are jointly retransmitting the PSSCHusing the shared resource. In a sixth aspect, alone or in combinationwith one or more of the first through fifth aspects, the power offset isproportional to an amount of radio resources associated with theconfigured grant used for initially transmitting the PSSCH.

In a seventh aspect, alone or in combination with one or more of thefirst through sixth aspects, process 1000 includes receiving, via aPSFCH, feedback from the receiver UE indicating that the receiver UEfailed to successfully receive the PSSCH, and determining whether toretransmit the PSSCH based at least in part on a group configured grantindicating a priority associated with the transmitter UE and a number ofhighest priority transmitter UEs that are configured to retransmit thePSSCH. In an eighth aspect, alone or in combination with one or more ofthe first through seventh aspects, process 1000 includes retransmittingthe PSSCH using a sidelink resource associated with the group configuredgrant based at least in part on determining that the number of highestpriority transmitter UEs include the transmitter UE. In a ninth aspect,alone or in combination with one or more of the first through eighthaspects, process 1000 includes refraining from retransmitting the PSSCHbased at least in part on determining that the number of highestpriority transmitter UEs do not include the transmitter UE. In a tenthaspect, alone or in combination with one or more of the first throughninth aspects, the number of highest priority transmitter UEs that areconfigured to retransmit the PSSCH is indicated in RRC signaling or DCIactivating the group configured grant. In an eleventh aspect, alone orin combination with one or more of the first through tenth aspects, thepriority associated with the transmitter UE is determined based at leastin part on a time-varying rule indicated in RRC signaling. In a twelfthaspect, alone or in combination with one or more of the first througheleventh aspects, process 1000 includes decoding the feedback receivedvia the PSFCH for the transmitter UE and for one or more othertransmitter UEs associated with the group configured grant.

In a thirteenth aspect, alone or in combination with one or more of thefirst through twelfth aspects, process 1000 includes receiving, via aPSFCH, feedback from the receiver UE indicating that the receiver UEfailed to successfully receive the PSSCH, where the feedback includesone or more dynamic grants for retransmission of the PSSCH by one ormore transmitter UEs. In a fourteenth aspect, alone or in combinationwith one or more of the first through thirteenth aspects, process 1000includes retransmitting the PSSCH based at least in part on the one ormore dynamic grants scheduling a retransmission of the PSSCH by thetransmitter UE.

In a fifteenth aspect, alone or in combination with one or more of thefirst through fourteenth aspects, process 1000 includes determining thatthe one or more dynamic grants do not schedule a retransmission of thePSSCH by the transmitter UE, and determining whether to retransmit thePSSCH based at least in part on a group configured grant indicating apriority associated with the transmitter UE and a number of highestpriority transmitter UEs that are configured to retransmit the PSSCH. Ina sixteenth aspect, alone or in combination with one or more of thefirst through fifteenth aspects, process 1000 includes retransmittingthe PSSCH using a sidelink resource associated with the group configuredgrant based at least in part on determining that the number of highestpriority transmitter UEs include the transmitter UE. In a seventeenthaspect, alone or in combination with one or more of the first throughsixteenth aspects, process 1000 includes refraining from retransmittingthe PSSCH based at least in part on determining that the number ofhighest priority transmitter UEs do not include the transmitter UE. Inan eighteenth aspect, alone or in combination with one or more of thefirst through seventeenth aspects, sidelink resources allocated to theretransmission of the PSSCH include a first portion associated with theone or more dynamic grants and a second portion associated with thegroup configured grant.

In a nineteenth aspect, alone or in combination with one or more of thefirst through eighteenth aspects, the transmitter UE is an S/A UE, andthe receiver UE is a PLC UE.

Although FIG. 10 shows example blocks of process 1000, in some aspects,process 1000 may include additional blocks, fewer blocks, differentblocks, or differently arranged blocks than those depicted in FIG. 10 .Additionally, or alternatively, two or more of the blocks of process1000 may be performed in parallel.

FIG. 11 is a block diagram of an example apparatus 1100 for wirelesscommunication in accordance with various aspects of the presentdisclosure. The apparatus 1100 may be a transmitter UE, or a transmitterUE may include the apparatus 1100. In some aspects, the apparatus 1100includes a reception component 1102, a communication manager 1104, and atransmission component 1106, which may be in communication with oneanother (e.g., via one or more buses). As shown, the apparatus 1100 maycommunicate with another apparatus 1108 (e.g., a receiver UE, a basestation, or another wireless communication device) using the receptioncomponent 1102 and the transmission component 1106.

In some aspects, the apparatus 1100 may be configured to perform one ormore operations described herein in connection with FIG. 7 , FIGS.8A-8C, and/or FIGS. 9A-9D. Additionally, or alternatively, the apparatus1100 may be configured to perform one or more processes describedherein, such as process 1000 of FIG. 10 . In some aspects, the apparatus1100 may include one or more components of the UE 120 described above inconnection with FIG. 2 .

The reception component 1102 may receive communications, such asreference signals, control information, data communications, or acombination thereof, from the apparatus 1108. The reception component1102 may provide received communications to one or more other componentsof the apparatus 1100, such as the communication manager 1104. In someaspects, the reception component 1102 may perform signal processing onthe received communications (e.g., filtering, amplification,demodulation, analog-to-digital conversion, demultiplexing,deinterleaving, de-mapping, equalization, interference cancellation,decoding, and/or the like), and may provide the processed signals to theone or more other components. In some aspects, the reception component1102 may include one or more antennas, a demodulator, a MIMO detector, areceive processor, a controller/processor, a memory, or a combinationthereof, of the UE 120 described above in connection with FIG. 2 .

The transmission component 1106 may transmit communications, such asreference signals, control information, data communications, or acombination thereof, to the apparatus 1108. In some aspects, thecommunication manager 1104 may generate communications and may transmitthe generated communications to the transmission component 1106 fortransmission to the apparatus 1108. In some aspects, the transmissioncomponent 1106 may perform signal processing on the generatedcommunications (e.g., filtering, amplification, modulation,digital-to-analog conversion, multiplexing, interleaving, mapping,encoding, and/or the like), and may transmit the processed signals tothe apparatus 1108. In some aspects, the transmission component 1106 mayinclude one or more antennas, a modulator, a transmit MIMO processor, atransmit processor, a controller/processor, a memory, or a combinationthereof, of the UE 120 described above in connection with FIG. 2 . Insome aspects, the transmission component 1106 may be co-located with thereception component 1102 in a transceiver.

The communication manager 1104 may transmit or may cause thetransmission component 1106 to transmit, to a receiver UE, a stage oneSCI message that indicates one or more sub-channels occupied by theapparatus 1100. The communication manager 1104 may transmit or may causethe transmission component 1106 to transmit, to the receiver UE, a PSSCHusing the one or more sub-channels occupied by the apparatus 1100according to a configured grant associated with the apparatus 1100. Insome aspects, the communication manager 1104 may include acontroller/processor, a memory, or a combination thereof, of the UE 120described above in connection with FIG. 2 .

In some aspects, the communication manager 1104 may include a set ofcomponents, such as an indication component 1110 and/or the like.Alternatively, the set of components may be separate and distinct fromthe communication manager 1104. In some aspects, one or more componentsof the set of components may include or may be implemented within acontroller/processor, a memory, or a combination thereof, of the UE 120described above in connection with FIG. 2 . Additionally, oralternatively, one or more components of the set of components may beimplemented at least in part as software stored in a memory. Forexample, a component (or a portion of a component) may be implemented asinstructions or code stored in a non-transitory computer-readable mediumand executable by a controller or a processor to perform the functionsor operations of the component.

The indication component 1110 may configure a stage one SCI message toindicate one or more sub-channels occupied by the apparatus 1100. Thetransmission component 1106 may transmit the stage one SCI message to areceiver UE, and the transmission component 1106 may further transmit,to the receiver UE, a PSSCH using the one or more sub-channels occupiedby the apparatus 1100 according to a configured grant associated withthe apparatus 1100.

The number and arrangement of components shown in FIG. 11 are providedas an example. In practice, there may be additional components, fewercomponents, different components, or differently arranged componentsthan those shown in FIG. 11 . Furthermore, two or more components shownin FIG. 11 may be implemented within a single component, or a singlecomponent shown in FIG. 11 may be implemented as multiple, distributedcomponents. Additionally, or alternatively, a set of (one or more)components shown in FIG. 11 may perform one or more functions describedas being performed by another set of components shown in FIG. 11 .

The foregoing disclosure provides illustration and description, but isnot intended to be exhaustive or to limit the aspects to the preciseform disclosed. Modifications and variations may be made in light of theabove disclosure or may be acquired from practice of the aspects.

As used herein, the term “component” is intended to be broadly construedas hardware, firmware, and/or a combination of hardware and software. Asused herein, a processor is implemented in hardware, firmware, and/or acombination of hardware and software. It will be apparent that systemsand/or methods described herein may be implemented in different forms ofhardware, firmware, and/or a combination of hardware and software. Theactual specialized control hardware or software code used to implementthese systems and/or methods is not limiting of the aspects. Thus, theoperation and behavior of the systems and/or methods were describedherein without reference to specific software code—it being understoodthat software and hardware can be designed to implement the systemsand/or methods based, at least in part, on the description herein.

As used herein, satisfying a threshold may, depending on the context,refer to a value being greater than the threshold, greater than or equalto the threshold, less than the threshold, less than or equal to thethreshold, equal to the threshold, not equal to the threshold, and/orthe like.

Even though particular combinations of features are recited in theclaims and/or disclosed in the specification, these combinations are notintended to limit the disclosure of various aspects. In fact, many ofthese features may be combined in ways not specifically recited in theclaims and/or disclosed in the specification. Although each dependentclaim listed below may directly depend on only one claim, the disclosureof various aspects includes each dependent claim in combination withevery other claim in the claim set. A phrase referring to “at least oneof” a list of items refers to any combination of those items, includingsingle members. As an example, “at least one of: a, b, or c” is intendedto cover a, b, c, a-b, a-c, b-c, and a-b-c, as well as any combinationwith multiples of the same element (e.g., a-a, a-a-a, a-a-b, a-a-c,a-b-b, a-c-c, b-b, b-b-b, b-b-c, c-c, and c-c-c or any other ordering ofa, b, and c).

No element, act, or instruction used herein should be construed ascritical or essential unless explicitly described as such. Also, as usedherein, the articles “a” and “an” are intended to include one or moreitems and may be used interchangeably with “one or more.” Further, asused herein, the article “the” is intended to include one or more itemsreferenced in connection with the article “the” and may be usedinterchangeably with “the one or more.” Furthermore, as used herein, theterms “set” and “group” are intended to include one or more items (e.g.,related items, unrelated items, a combination of related and unrelateditems, and/or the like), and may be used interchangeably with “one ormore.” Where only one item is intended, the phrase “only one” or similarlanguage is used. Also, as used herein, the terms “has,” “have,”“having,” and/or the like are intended to be open-ended terms. Further,the phrase “based on” is intended to mean “based, at least in part, on”unless explicitly stated otherwise. Also, as used herein, the term “or”is intended to be inclusive when used in a series and may be usedinterchangeably with “and/or,” unless explicitly stated otherwise (e.g.,if used in combination with “either” or “only one of”).

What is claimed is:
 1. A method of wireless communication performed by atransmitter user equipment (UE), comprising: transmitting, to a receiverUE, a stage one sidelink control information (SCI) message thatindicates one or more sub-channels occupied by the transmitter UE; andtransmitting, to the receiver UE and based at least in part ontransmitting the stage one SCI message, a physical sidelink sharedchannel (PSSCH) message using the one or more sub-channels occupied bythe transmitter UE, wherein the PSSCH message includes receiver-orientedconfigured grant data associated with a receiver-oriented configuredgrant associated with enabling the receiver UE to receive a sidelinkdata transmission in a particular transmission time interval withoutrequiring a dynamic grant to schedule the sidelink data transmission,and wherein the stage one SCI message and the receiver-orientedconfigured grant include all parameters and related informationassociated with transmitting the receiver-oriented configured grant datavia the PSSCH message.
 2. The method of claim 1, wherein the stage oneSCI message includes a heartbeat signal to maintain a unicast link fromthe transmitter UE to the receiver UE.
 3. The method of claim 1, furthercomprising: transmitting, to the receiver UE, a stage two SCI messagethat includes one or more parameters to override a modulation and codingscheme configuration.
 4. The method of claim 1, further comprising:receiving, via a physical sidelink feedback channel (PSFCH), feedbackfrom the receiver UE indicating whether the receiver UE successfullyreceived the PSSCH message; and retransmitting the PSSCH message using ashared resource associated with the receiver-oriented configured grantbased at least in part on the feedback indicating that the receiver UEfailed to successfully receive the PSSCH message, wherein thetransmitter UE and one or more other transmitter UEs jointly retransmitthe PSSCH message using the shared resource.
 5. The method of claim 4,further comprising: transmitting, jointly with the one or more othertransmitter UEs, an additional stage one SCI message indicating theshared resource used to retransmit the PSSCH message.
 6. The method ofclaim 4, wherein the PSSCH message is retransmitted using a power offsetthat is based at least in part on a number of the one or more othertransmitter UEs that are jointly retransmitting the PSSCH message usingthe shared resource.
 7. The method of claim 6, wherein the power offsetis proportional to an amount of radio resources associated with thereceiver-oriented configured grant used for initially transmitting thePSSCH message.
 8. The method of claim 1, further comprising: receiving,via a physical sidelink feedback channel (PSFCH), feedback from thereceiver UE indicating that the receiver UE failed to successfullyreceive the PSSCH message; and determining whether to retransmit thePSSCH message based at least in part on a group configured grantindicating a priority associated with the transmitter UE and a number ofhighest priority transmitter UEs that are configured to retransmit thePSSCH message.
 9. The method of claim 8, further comprising:retransmitting the PSSCH message using a sidelink resource associatedwith the group configured grant based at least in part on determiningthat the number of highest priority transmitter UEs include thetransmitter UE.
 10. The method of claim 8, further comprising:refraining from retransmitting the PSSCH message based at least in parton determining that the number of highest priority transmitter UEs donot include the transmitter UE.
 11. The method of claim 8, wherein thenumber of highest priority transmitter UEs that are configured toretransmit the PSSCH message is indicated in radio resource controlsignaling or downlink control information activating the groupconfigured grant.
 12. The method of claim 8, wherein the priorityassociated with the transmitter UE is determined based at least in parton a time-varying rule indicated in radio resource control signaling.13. The method of claim 8, further comprising: decoding the feedbackreceived via the PSFCH for the transmitter UE and for one or more othertransmitter UEs associated with the group configured grant.
 14. Themethod of claim 1, further comprising: receiving, via a physicalsidelink feedback channel (PSFCH), feedback from the receiver UEindicating that the receiver UE failed to successfully receive the PSSCHmessage, wherein the feedback includes one or more dynamic grants forretransmission of the PSSCH message.
 15. The method of claim 14, furthercomprising: retransmitting the PSSCH message based at least in part onthe one or more dynamic grants scheduling a retransmission of the PSSCHmessage by the transmitter UE.
 16. The method of claim 15, furthercomprising: determining that the one or more dynamic grants do notschedule a retransmission of the PSSCH message by the transmitter UE;and determining whether to retransmit the PSSCH message based at leastin part on a group configured grant indicating a priority associatedwith the transmitter UE and a number of highest priority transmitter UEsthat are configured to retransmit the PSSCH message.
 17. The method ofclaim 16, further comprising: retransmitting the PSSCH message using asidelink resource associated with the group configured grant based atleast in part on determining that the number of highest prioritytransmitter UEs include the transmitter UE.
 18. The method of claim 16,further comprising: refraining from retransmitting the PSSCH messagebased at least in part on determining that the number of highestpriority transmitter UEs do not include the transmitter UE.
 19. Themethod of claim 16, wherein sidelink resources allocated to theretransmission of the PSSCH message include a first portion associatedwith the one or more dynamic grants and a second portion associated withthe group configured grant.
 20. The method of claim 1, wherein thetransmitter UE is a sensor/actuator UE, and wherein the receiver UE is aprogrammable logic controller UE.
 21. A transmitter user equipment (UE)for wireless communication, comprising: a memory; and one or moreprocessors coupled to the memory, the one or more processors configuredto: transmit, to a receiver UE, a stage one sidelink control information(SCI) message that indicates one or more sub-channels occupied by thetransmitter UE; and transmit, to the receiver UE and based at least inpart on transmitting the stage one SCI message, a physical sidelinkshared channel (PSSCH) message using the one or more sub-channelsoccupied by the transmitter UE, wherein the PSSCH message includesreceiver-oriented configured grant data associated with areceiver-oriented configured grant associated with enabling the receiverUE to receive a sidelink data transmission in a particular transmissiontime interval without requiring a dynamic grant to schedule the sidelinkdata transmission, and wherein the stage one SCI message and thereceiver-oriented configured grant include all parameters and relatedinformation associated with transmitting the receiver-orientedconfigured grant data via the PSSCH message.
 22. The transmitter UE ofclaim 21, wherein the stage one SCI message includes a heartbeat signalto maintain a unicast link from the transmitter UE to the receiver UE.23. The transmitter UE of claim 21, wherein the one or more processorsare further configured to: transmit, to the receiver UE, a stage two SCImessage that includes one or more parameters to override a modulationand coding scheme configuration.
 24. The transmitter UE of claim 21,wherein the one or more processors are further configured to: receive,via a physical sidelink feedback channel (PSFCH), feedback from thereceiver UE indicating whether the receiver UE successfully received thePSSCH message; and retransmit the PSSCH message using a shared resourceassociated with the receiver-oriented configured grant based at least inpart on the feedback indicating that the receiver UE failed tosuccessfully receive the PSSCH message, wherein the transmitter UE andone or more other transmitter UEs jointly retransmit the PSSCH messageusing the shared resource.
 25. The transmitter UE of claim 24, whereinthe one or more processors are further configured to: transmit, jointlywith the one or more other transmitter UEs, an additional stage one SCImessage indicating the shared resource used to retransmit the PSSCHmessage.
 26. The transmitter UE of claim 24, wherein the PSSCH messageis retransmitted using a power offset that is based at least in part ona number of the one or more other transmitter UEs that are jointlyretransmitting the PSSCH message using the shared resource.
 27. Thetransmitter UE of claim 26, wherein the power offset is proportional toan amount of radio resources associated with the receiver-orientedconfigured grant used for initially transmitting the PSSCH message. 28.The transmitter UE of claim 21, wherein the one or more processors arefurther configured to: receive, via a physical sidelink feedback channel(PSFCH), feedback from the receiver UE indicating that the receiver UEfailed to successfully receive the PSSCH; and determine whether toretransmit the PSSCH message based at least in part on a groupconfigured grant indicating a priority associated with the transmitterUE and a number of highest priority transmitter UEs that are configuredto retransmit the PSSCH message.
 29. The transmitter UE of claim 28,wherein the one or more processors are further configured to: retransmitthe PSSCH message using a sidelink resource associated with the groupconfigured grant based at least in part on determining that the numberof highest priority transmitter UEs include the transmitter UE.
 30. Thetransmitter UE of claim 28, wherein the one or more processors arefurther configured to: refrain from retransmitting the PSSCH messagebased at least in part on determining that the number of highestpriority transmitter UEs do not include the transmitter UE.
 31. Thetransmitter UE of claim 28, wherein the number of highest prioritytransmitter UEs that are configured to retransmit the PSSCH message isindicated in radio resource control signaling or downlink controlinformation activating the group configured grant.
 32. The transmitterUE of claim 28, wherein the priority associated with the transmitter UEis determined based at least in part on a time-varying rule indicated inradio resource control signaling.
 33. The transmitter UE of claim 28,wherein the one or more processors are further configured to: decode thefeedback received via the PSFCH for the transmitter UE and for one ormore other transmitter UEs associated with the group configured grant.34. The transmitter UE of claim 21, wherein the one or more processorsare further configured to: receive, via a physical sidelink feedbackchannel (PSFCH), feedback from the receiver UE indicating that thereceiver UE failed to successfully receive the PSSCH message, whereinthe feedback includes one or more dynamic grants for retransmission ofthe PSSCH message.
 35. The transmitter UE of claim 34, wherein the oneor more processors are further configured to: retransmit the PSSCHmessage based at least in part on the one or more dynamic grantsscheduling a retransmission of the PSSCH message by the transmitter UE.36. The transmitter UE of claim 35, wherein the one or more processorsare further configured to: determine that the one or more dynamic grantsdo not schedule a retransmission of the PSSCH message by the transmitterUE; and determine whether to retransmit the PSSCH message based at leastin part on a group configured grant indicating a priority associatedwith the transmitter UE and a number of highest priority transmitter UEsthat are configured to retransmit the PSSCH message.
 37. The transmitterUE of claim 36, wherein the one or more processors are furtherconfigured to: retransmit the PSSCH message using a sidelink resourceassociated with the group configured grant based at least in part ondetermining that the number of highest priority transmitter UEs includethe transmitter UE.
 38. The transmitter UE of claim 36, wherein the oneor more processors are further configured to: refrain fromretransmitting the PSSCH message based at least in part on determiningthat the number of highest priority transmitter UEs do not include thetransmitter UE.
 39. The transmitter UE of claim 36, wherein sidelinkresources allocated to the retransmission of the PSSCH message include afirst portion associated with the one or more dynamic grants and asecond portion associated with the group configured grant.
 40. Thetransmitter UE of claim 21, wherein the transmitter UE is asensor/actuator UE, and wherein the receiver UE is a programmable logiccontroller UE.
 41. A non-transitory computer-readable medium storing oneor more instructions for wireless communication, the one or moreinstructions comprising: one or more instructions that, when executed byone or more processors of a transmitter user equipment (UE), cause theone or more processors to: transmit, to a receiver UE, a stage onesidelink control information (SCI) message that indicates one or moresub-channels occupied by the transmitter UE; and transmit, to thereceiver UE and based at least in part on transmitting the stage one SCImessage, a physical sidelink shared channel (PSSCH) message using theone or more sub-channels occupied by the transmitter UE, wherein thePSSCH message includes receiver-oriented configured grant dataassociated with a receiver-oriented configured grant associated withenabling the receiver UE to receive a sidelink data transmission in aparticular transmission time interval without requiring a dynamic grantto schedule the sidelink data transmission, and wherein the stage oneSCI message and the receiver-oriented configured grant include allparameters and related information associated with transmitting thereceiver-oriented configured grant data via the PSSCH message.
 42. Anapparatus for wireless communication, comprising: means fortransmitting, to a receiver user equipment (UE), a stage one sidelinkcontrol information (SCI) message that indicates one or moresub-channels occupied by the apparatus; and means for transmitting, tothe receiver UE and based at least in part on the means for transmittingthe stage one SCI message, a physical sidelink shared channel (PSSCH)message using the one or more sub-channels occupied by the apparatus,wherein the PSSCH message includes receiver-oriented configured grantdata associated with a receiver-oriented configured grant associatedwith enabling the apparatus to receive a sidelink data transmission in aparticular transmission time interval without requiring a dynamic grantto schedule the sidelink data transmission, and wherein the stage oneSCI message and the receiver-oriented configured grant include allparameters and related information associated with transmitting thereceiver-oriented configured grant data via the PSSCH message.